The present invention relates to a device for protecting physiological pathways subjected to explorations performed with diagnostic and/or operating instruments.
In medical work it is currently often necessary to explore and inspect organs of the human body by introducing particular instruments which use optical fibers in body passages.
This is the case in particular of urethroscopies, during which damage is usually caused to the tissues that compose the urethral canal through which the instruments pass in order to reach the bladder.
This is particularly evident when these passages are repeated at short intervals, for example to change the instrument, as usually occurs when replacing the diagnostic instrument with the operating instrument.
For example, it can also become necessary to insert a permanent catheter of the type known as the Foley catheter, which, despite being made of polyurethane, silicone, latex or other equivalent material and despite being inserted in the urethra with the aid of lubricants and of a thin rigid sound, can cause further damage to a tissue which has already suffered alterations and/or lacerations.
This damage is due to the particular concertina-like configuration of the tissue of the urethra, which does not form a true open canal but rather a canal which can be considered as such only once it is fully open and dilated by a foreign object.
Furthermore, in this case the tissue is more or less consistent and offers a variable resistance to the passage of the instrument, which is followed by the movement of the concertina-like mucous membrane.
The simple dilation of the canal actually produces very little or no damage.
On the contrary, the insertion of a foreign object having a considerable diameter causes important damage; for example, a diameter of 8 mm for an adult and 6 mm for children is sufficient.
Furthermore, if this insertion is repeated at closely spaced intervals, the damage can become more severe, although not permanent, and usually heals within 4-10 days, during which pain persists and is subsequently replaced by discomfort.
As a first step, the possibility of using a protective device substantially constituted by a tube of netting, capable of dilating when an instrument having a larger diameter than the tube passes, was considered.
However, such device unfortunately causes traumas in the tissue of the urethra when the netting, after elongating, returns to its original dimensions, entraining parts of the previously dilated tissue in the meshes that close.
Furthermore, since the meshes of the tube of netting are very thin in order to avoid increasing excessively the diameter of the passage canal, said meshes can become a sharp blade.
It should also be added that the netting tube does not allow the passage of a Foley catheter due to the presence therein of the Y-shaped union for inflating the balloon for retaining it.
Another drawback observed in the described netting tube occurs during elongation, when as the diameter increases the length of the tube decreases, but this variation is not acceptable.
A protective device obtained by mutually joining two half-tubes at two sides which can be semirigid or partially flexible was then considered.
However, this produces two parts which have different lengths according to the diameter to which they expand during the insertion of the instrument; moreover, it has been observed that the total diameter, constituted by the diameter of the instrument plus the diameter of the tube, increases considerably.
Even with this type of protective device, it is not possible to insert a Foley catheter for the same reasons mentioned for the netting tube.